When Korean actor and singer Park Yong-ha hanged himself on his bedpost on June 30 last year, it sent shock waves around the world.

In Turkey, thousands of kilometres away, fans expressed their grief at the death of the 32-year-old actor, internationally famous for his role in the popular drama Winter Sonata.

It later emerged that Park had been under immense pressure after discovering that his father had terminal cancer.

'It is truly heart-wrenching,' said one Turkish internet user calling herself 'badgirl', in a post about Park's suicide.

A year later, 1,500 fans from Japan visited South Korea's Gyeonggi province, where Park's body had been laid to rest, to attend a memorial ceremony for the late idol. In front of Park's portrait and an altar burning incense despite the pouring rain, fans wiped away tears for their 'rain man'.

Park's death is one of several prominent suicides in South Korea and elsewhere that have prompted warnings by health officials of copycat suicides among the general population.

The phenomenon can be traced back to the 18th century, when a string of copycat suicides were reported across Europe after the publication of German writer Johann Wolfgang von Goethe's novel The Sorrows of Young Werther.

The book - about a man who takes his own life after losing his true love - was published in 1774.

A more recent case is that of the probable suicide of actress Marilyn Monroe through an overdose of sleeping pills in 1962. Researchers found a 12 per cent increase in suicides in the United States in the month that followed.

For the past few years South Korea has had the highest number of dignitaries killing themselves, ranging from its former president to corporate leaders and theatre icons.

In show business alone, nearly a dozen Korean film stars committed suicide because of scandals, illness or the burden of disparaging attacks on the internet.

Choi Jin-sil, the 'nation's actress', was among the most prominent. She took her own life in October 2008 after she was accused of pressuring another actor who owed her money. The suicide of that star, Ahn Jae-hwan, a few weeks earlier drew national attention.

Given the success of the so-called Korean Wave, - the spread of Korean pop culture around the world, particularly to China - there are now fears that the examples set by desperate Korean celebrities could have an impact beyond the country's borders. 'What is worthy of concern is that the impact of celebrity suicide can go beyond borders,' Wang Xiangdong, the World Health Organisation's regional adviser on mental health and injury prevention, said in a recent interview.

Wang, based in the WHO regional office in the Philippines, has been involved in the global effort to help stem suicides, which have become one of the major causes of death in many countries, especially among teenagers. He is the regional adviser to the WHO's Western Pacific region, which covers 37 countries and areas.

About one million people commit suicide each year worldwide, according to the WHO, and global suicide rates have increased by 60 per cent in the past 45 years.

This has prompted health experts to brand it a disease and urge national governments to draw up measures to deal with the problem.

Wang said governments should focus on the impact of celebrity suicides in the region, which are often glorified by the media.

The number of suicides in South Korea increased from an average of 1,100 a year to an annual toll of nearly 1,800 after Choi's death, according to statistics quoted there.

The behaviour of stars has the potential to influence more people further afield because of the internet and social media, according to a Hong Kong scholar who advocates more careful treatment of celebrity suicide by the media.

'Now, if stars become popular in the region, their influence is without borders,' said Paul Yip Siu-fai, founding director of the Hong Kong Jockey Club Centre for Suicide Research and Prevention and a professor of social work and social administration at the University of Hong Kong.

Yip co-authored a study in 2009 which identified a link between an increase in suicides and the death of actor and singer Leslie Cheung Kwok-wing. Data collected from the Coroner's Court as well as the census department showed that the average number of suicides in Hong Kong increased in the month after Cheung killed himself in April 2003 - from 21.5 a week to 31.5.

The total number of suicides recorded that year, when Hong Kong was also hit by Sars (severe acute respiratory syndrome), rose to 1,200. The toll was fewer than 1,000 last year.

Yip said that while there had been few studies done on the impact of celebrity suicide in different countries, such research could be useful in helping governments to devise more effective strategies to tackle the problem.

The WHO is trying to deal with the issue at its roots. It recently initiated a project in collaboration with national governments to reach out to celebrities and try to educate them on suicide prevention.

Wang said that in South Korea, entertainers' associations will be contacted to ensure agents are aware of the signs of suicidal intent.

'Actors' agents should learn about the warning signs. They're the ones who can keep a close eye on the stars and they're the ones who can intervene,' Wang said.

Clarence Tsang Chin-kwok, executive director of the Samaritan Befrienders Hong Kong, said that celebrities should be setting an example for the public by seeking professional help when they encounter any emotional difficulties.

'Their behaviour has a huge impact on people - especially on teenagers. We hope that actors and actresses seek help if they start having suicidal thoughts,' Tsang said.